1. Field of the Invention
The present invention relates generally to a backlight split control apparatus and a backlight split control method using the same. More particularly, the present invention relates to a backlight split control apparatus and a backlight split control method using the same for regulating an adjustment value of a backlight to an optimal state, enhancing image quality, and raising efficiency of power consumption by adjusting a luminance of the backlight using mutually cooperative luminance information of divided sections of the backlight of a display device.
2. Description of the Related Art
A liquid crystal display device using an element not illuminating by itself, such as a LCD panel, requires a light source like a backlight unit. The conventional display turns on and off the entire backlight, whereas the recent display controls a luminance of the entire backlight for the sake of the reduction of the power consumption. This method can reduce the power consumption by decreasing the luminance in whole but is subject to deterioration of the image quality because the brightness of the entire screen lowers.
After the luminance control technique of the whole backlight, a method for controlling the luminance by splitting the backlight in one dimension and controlling each CCFL has been suggested, which can achieve the better performance than the luminance control of the whole backlight. However, since the physical limitation of the CCFL allows only the one-dimensional control, the adjustment on the detailed area is impossible.
As the backlight of TFT-LCD substitutes the CCFL with an LED, the two-dimensional area division and control of the backlight is feasible. In general, the two-dimensional division control of the backlight is referred to as a backlight local dimming control. The backlight local dimming control divides the backlight into two-dimensional M×N blocks, splits the luminance signal of an input image to match the backlight blocks, extracts the luminance signal within the divided region, and thus controls the luminance. This control method can reduce the power consumption and yield the good performance in terms of the contrast enhancement of the displayed image.
Unlike the adjustment of the luminance of the entire backlight, the method which splits the backlight into the multiple sections and controls the sections individually is subject to the variation of the backlight. Thus, it is necessary to take into account interference between the divided sections in the backlight because the luminance of the neighboring sections affects the luminance of the corresponding section. When the interference is not considered, the accurate backlight value is not calculated. The conventional method determines the luminance of each section of the backlight using merely the value extracted from the luminance distribution of the image without considering the influence from the neighboring sections, and thus suffers from the excessive control or a distortion.
Hence, what is needed is a method for dividing and controlling the backlight with a higher efficiency.